1. Field of the Invention
This invention relates generally to medical electrode systems and, in particular, to an independently deployable sealed defibrillator electrode for use with an automatic or semi-automatic external defibrillator (AED). The invention also relates to the method of use thereof.
2. Description of the Prior Art
One frequent consequence of heart attacks is the development of cardiac arrest associated with heart arrhythmias, such as ventricular fibrillation ("VF"). VF is caused by an abnormal and very fast electrical activity in the heart. During VF the heart cannot pump blood effectively. VF may be treated by applying an electric shock to the patient's heart through the use of a defibrillator. Defibrillation clears the heart of the abnormal electrical activity by creating a momentary asystole, thus giving the heart's natural pacemaker areas an opportunity to restore normal function. Because blood no longer pumps effectively during VF, the chance of surviving a heart attack decreases with time after the attack. Quick response by administering a defibrillating shock as soon as possible after the onset of VF is therefore often critically important.
Increasing the number of potential defibrillator operators who are trained in the proper use of an external defibrillator increases the likelihood that a trained defibrillator operator will be available during an emergency and thus could ultimately reduce the defibrillator deployment time. As the number of potential operators increases, however, the frequency with which each operator uses the skills developed during training decreases. Depending upon the amount of time since the defibrillator operator last used a defibrillator, review of electrode placement instructions will likely be required to determine correct placement of the electrode pads. Failure to apply the electrode pads correctly can reduce the amount of energy that is applied to the myocardium. Misapplied electrodes can allow the current to flow along the chest wall, thus missing the heart, and result in a failure of the defibrillation shock. Reviewing pad placement, while necessary, delays the speed with which defibrillation can be performed on the patient. With every second that passes, the likelihood of successfully restoring the patient's heart to a normal sinus rhythm decreases. Therefore, every step in the deployment and use of a defibrillator that can be streamlined is critical.
One time saving gain has been the development of electrode pads that eliminate the step of attaching electrode pads to the cable, and, for the most part, eliminate the need to untangle the cable. Morgan describes an example of such an electrode system in U.S. Pat. No. 5,466,244 for "Defibrillator Electrode System". Other electrode pad designs are known in the art. However, notwithstanding these improvements, electrode deployment and placement is still the most time consuming and difficult step in using an AED.
Currently available defibrillator electrode pads used with AEDs use two adhesive electrode pads adhered to a liner. Additionally, the electrodes are located within a heat sealed pouch. When the electrode pads are deployed during an emergency, the user must, at a minimum, open the bag and then peel the electrodes off the liner prior to attaching the electrodes to the patient. [See, e.g., Zoll stat.padz.TM..] Where the liner is not part of the bag, the user must also remove the liner from the bag prior to removing the electrodes. [See, e.g., Heartstream.RTM. ForeRunner.RTM. electrodes and Physio-Control.RTM. Fast-Patch.RTM. electrodes.] As a result, a minimum of two to three steps is required to deploy the electrode prior to attaching the electrodes to the victim. The more steps required to deploy the electrodes, the longer the victim must wait for the defibrillating shock.
Another problem with deploying electrodes stems from the fact that they can be awkward to use. For example, the electrodes can fold upon itself requiring the user to spend time unfolding the electrode.
What is needed is an easy to use electrode system that enables a rescuer to quickly and accurately apply the electrode pads to a victim of sudden cardiac arrest.